What's the difference between occasional and periodical?

Occasional


Definition:

  • (a.) Of or pertaining to an occasion or to occasions; occuring at times, but not constant, regular, or systematic; made or happening as opportunity requires or admits; casual; incidental; as, occasional remarks, or efforts.
  • (a.) Produced by accident; as, the occasional origin of a thing.

Example Sentences:

  • (1) Histiocytes, lymphocytes, immunoblasts, and plasma cells were present in expanded paracortical regions which encroached on, and occasionally effaced, lymphoid follicles.
  • (2) While they may always be encumbered by censorship in a way that HBO is not, the success of darker storylines, antiheroes and the occasional snow zombie will not be lost in an entertainment industry desperate to maintain its share of the audience.
  • (3) Occasional vomits occur postoperatively in over half of patients but we are sceptical of the value of graded postoperative feeding regimens.
  • (4) The epithelium of Brunner's gland stained intensely with Ricinus communis agglutinin-I (RCA-I), succinylated-WGA (S-WGA) and wheat-germ agglutinin (WGA), moderately with Bandeirea simplicifolia agglutinin-I (BS-I), Concanavalia ensiformis agglutinin (Con A) peanut agglutinin (PNA) and Ulex europaeus agglutinin-I (UEA-I) and occasionally with Dolichos biflorus agglutinin (DBA), Lens culinaris agglutinin (LCA) and soybean agglutinin (SBA).
  • (5) Our interest in the role of association brain structures during this behavior is not occasional.
  • (6) The region of the tentorium and straight sinus can occasionally give rise to a vermiform appearance (the "AVM artifact").
  • (7) It should also be realised that, in a very few hospitals, swabs which do not have an opaque marker may occasionally be used in theatre.
  • (8) He was often detained and occasionally beaten when he returned to Minsk for demonstrations, but “if he thought it was professional duty to uncover something, he did that no matter what threats were made,” Kalinkina said.
  • (9) Tissue sections, taken from foliate and circumvallate papillae, generally revealed taste buds in which all cells were immunoreactive; however, occasionally some taste buds were found to contain highly reactive individual cells adjacent to non-reactive cells.
  • (10) Her success has not been universally welcomed - anonymous colleagues are occasionally quoted in the media portraying her as "ambitious" and "bossy".
  • (11) Strains showing occasional antagonism at a particular proportion of concentrations of the test combination, were found to only be indifferent when the mean index of the fractional inhibition concentration of all checkerboard combinations was calculated.
  • (12) Occasionally, these aggregates coagulate and contract into a dense gel in the absence of MgATP or CaATP.
  • (13) The virus neutralizing (VN) titers were occasionally lower where the polyvalent vaccines were used when compared to those from chickens given the monovalent vaccines.
  • (14) Combining drugs may only occasionally be advisable to supplement a desired effect or to attenuate an unwanted one.
  • (15) Stimulation of this mechanism produced an average 58.9% reduction of the heart rate (calculated from 55 responsive points having more than 40% reduction) associated mostly with hypotension, or no change or occasionally a slight increase of the arterial blood pressure.
  • (16) In the progeny of the surviving males, neither translocations nor independent fragments are found; indirect evidence indicated the occasional presence of inversions.
  • (17) Occasionally symptomatic kinking of the internal carotid artery will require correction.
  • (18) At thoracic levels occasional neurons of the intermediolateral column cell group were NGF receptor positive.
  • (19) The PAF receptor antagonist SRI 63-072 in a dose of 0.6 mg, reversed by 70% the reduction of coronary flow within 2-4 min after its addition to the perfusate; ED50 was 0.4 mg. Bradycardia and arrhythmia were reduced; however, the normal electrical activity was only occasionally restored.
  • (20) Staphylococci were the predominant inhabitants of normal skin, whereas micrococci were found only occasionally in this environment.

Periodical


Definition:

  • (a.) Of or pertaining to a period or periods, or to division by periods.
  • (a.) Performed in a period, or regular revolution; proceeding in a series of successive circuits; as, the periodical motion of the planets round the sun.
  • (a.) Happening, by revolution, at a stated time; returning regularly, after a certain period of time; acting, happening, or appearing, at fixed intervals; recurring; as, periodical epidemics.
  • (a.) Of or pertaining to a period; constituting a complete sentence.
  • (n.) A magazine or other publication which appears at stated or regular intervals.

Example Sentences:

  • (1) Without medication atypical ventricular tachycardia develops, in the author's opinion, most probably when bradycardia has persisted for a prolonged period.
  • (2) Disease stabilisation was associated with prolonged periods of comparatively high plasma levels of drug, which appeared to be determined primarily by reduced drug clearance.
  • (3) Although the mean values for all hemodynamic variables between the two placebo periods were minimally changed, the differences in individual patients were striking.
  • (4) It was shown in experiments on four dogs by the conditioned method that the period of recovery of conditioned activity after one hour ether anaesthesia tested 7 to 7.5 days.
  • (5) Under blood preservation conditions the difference of the rates of ATP-production and -consumption is the most important factor for a high ATP-level over long periods.
  • (6) No significant change occurred in the bacterial population of our hospital unit during the period of the study (more than 3 years).
  • (7) The secondary leukemia that occurred in these patients could be distinguished from the secondary leukemia that occurs after treatment with alkylating agents by the following: a shorter latency period; a predominance of monocytic or myelomonocytic features; and frequent cytogenetic abnormalities involving 11q23.
  • (8) Sixteen patients in whom schizophrenia was initially diagnosed and who were treated with fluphenazine enanthate or decanoate developed severe depression for a short period after the injection.
  • (9) During the study period four family outbreaks and seven recurrences of infection were observed.
  • (10) After a period on fat-rich diet the patient's physical fitness was increased and the recovery period after the acute load was shorter.
  • (11) During this period he developed autoimmune haemolytic anaemia, a rare complication of myelofibrosis.
  • (12) Pituitary weight, mitotic index and chromosomes were studied in male rats following a single or repeated dose of estradiol-benzoate for a total period of 210 days.
  • (13) Most thyroid hormone actions, however, appear in the perinatal period, and infants with thyroid agenesis appear normal at birth and develop normally with prompt neonatal diagnosis and treatment.
  • (14) Maximal aberration yields were observed for 2,4-diaminotoluene, 2,6-diaminotoluene and cytosine beta-D-arabinofuranoside from 17 to 21 h, eugenol from 15 to 21 h, cadmium sulfate from 15 to 24 h and 2-aminobiphenyl, from 17 to 24 h. For adriamycin at 1 microM, the % aberrant cells remained elevated throughout the period from 9 to 29 h, while small increases at 0.1 microM ADR were found only at 13 and at 25 h. For most chemicals the maximal aberration yield occurred at a different time for each concentration tested.
  • (15) Accuracy of discrimination of letters at various preselected distances was determined each session while Ortho-rater examinations were given periodically throughout training.
  • (16) During electrophysiologic study, the effect of propafenone on the effective refractory period of the accessory pathway was determined, as well as its effect during orthodromic atrioventricular (AV) reentrant tachycardia and atrial fibrillation.
  • (17) Time-series analysis and multiple-regression modeling procedures were used to characterize changes in the overall incidence rate over the study period and to describe the contribution of additional measures to the dynamics of the incidence rates.
  • (18) Throughout the period of rehabilitation, the frequent changes of a patient's condition may require a process of ongoing evaluation and appropriate adjustments in the physical therapy program.
  • (19) Anthropometric and nutritional (serum albumin and transferrin) values were normal in both groups both at the beginning and at the end of the treatment period.
  • (20) Analysis of conjugated discharges ACHs showed that they appeared predominantly periodically (87% of cases).